See I told you it is confusing ! You are right, it's not EGL that's different, it's where you get the surface for EGL to use that is different.Brian Beuken wrote: ↑Thu Jan 23, 2020 9:52 amNo, egl is available, that was never an issue, only the means of getting on screen was confusing on 3B, I used DispmanX (we discussed why before) and it workes perfectly well. here for example is my usual RPi (not 4) setup which works finePeterO wrote: ↑Thu Jan 23, 2020 7:05 amI've not looked back to my 3B+ since I got a 4B, but it is my understanding that the EGL interface is only available on the 4B and that on earlier models you still have to use DispmanX to get a rendering surface. But I could be wrong
But I've often said that the documentation on the whole graphics stack is lacking and there is no single place that clearly explains the relationships between parts and what is/is not available on different models and with different bits of software and firmware enabled.
Pre Pi4 it was DispmanX
Post Pi4 it is X11 (which is why you can now display openGLES in an X11 window (or even in a GTK+ widget).
Is it ? I though the "compositor" got in on the act somewhere (but where is the diagram that shows how it all fits together ????)I realise now effectivly X11 is pumping that dispmanX bitmap to the screen every frame, but thats fine.